Bridge for pianofortes and like stringed musical instruments



Dec. 4 1923. 1,476,014

J. G. JONES BRIDGE FOR PIANOFORTES AND LIKE STRINGED MUSICAL INSTRUMENTS Filfid D60. 2. 1922 jaw 3. ma

Nl/f/V b dew Patented Dec. 4, 1923.

UNITED STATES JESSE GEORGE JONES, OF EAST HAM, ENGLAND.

BRIDGE FOB PIANOFORTES AND LIKE STRINGED MUSICAL INSTRUMENTS.

Application filed December 2, 1922. Serial No. 604,471.

To aZZ whom 2'6 may concern.

Be it known that I, .lnssr. Gnonen .loNns, a British subject, residin at 5 Byron Avenue, East Ham, Essex, England have invented new and useful Improved Bridge for Pianofortes and Like Stringed Musical Instruments, of which the following is a specification.

This invention relates to improvements in bridges of pianofortes and like stringed musical instruments and has for its primary object to obtain a richer and more powerful tone with such instruments.

The principle on which my invention is based is the restriction of the passage for the wave stresses after they have fully developed in the string-carrying portion of the bridge so that their intensity is increased before transmission to thebreast or soundboard of the musical instrument.

A bridge for pianofortes and like stringed musical instruments according to this invention has a longitudinal channel in its under face terminating short of the ends, passages being bored through the body of the bridge from the end faces thereof to the said channel.

The under face is left intact at the ends of the bridge so that the strength of the bridge structure to withstand the load imposed on it by the strings and its rigidity for properly transmitting the wave stresses shall not unduly be weakened by the reduction of the area of supporting surface due to the channeling. It is found, however, that a richer and stronger tone is givento the instrument by forming a continuous air passage through the whole length of the bridge. For these reasons passages are bored through the end portions of the bridge body rather than continuing the channel throughout the whole length of the under face. The under face of the bridge is also provided with lateral channels at intervals along its length so as further to restrict the passages for the wave stresses just before they are transmitted to the sound board of the instrument.

According to a modification cylindrical passages are bored into the body of the bridge through and perpendicular to the under face, these passages terminating short of the upper face of the bridge and being placed into communication with atmosphere by means of holes in the side walls of the bridge.

In order that this invention may be more clearly understood an embodiment thereof will now be described with reference to the accompanying drawings in which Figure 1 is an inverted plan view of a pianofortc bridge.

Figure 2 is an uprightsection of the same on the line AA of Figure 1, and

Figure 3 is an upri ht end elevation.

Referring to the drawings, which illustrate a pianoforte bridge generally of the type well known in the art, but modified in accordance with my invention, 1 is a longitudinal channel in the supporting base 2 of the bridge. This channel 1 terminates short of the extremities of the bridge but is con tinued therethrough into communication with atmosphere by way of bores 3. Tunnels 4 are bored into the sides of the bridge at predetermined intervals. These tunnels may in some cases be disposed with advantage in staggered relationship on either side of the bridge instead of in alignment as shown in Figure 1.

According to a modification vertical bores such as 5 are formed at predetermined intervals in the walls of the bridge and lateral bores 6 establish communication therebetween and atmosphere.

The effect of the main channel 1 is to reduce the cross-sectional area of the passage for the wave stresses emanating from the string-carrying or body portion 7 of the bridge. By this means the intensity of the vibrations, which fully develop in the body portion of the bridge, is increased just before transmission to the breast or soundboard of the instrument. It is found in practice that the volume and quality of tone emanating from the instrument is thereby considerably improved.

The tunnels 1- and bores 3 serve to maintain free communication between the channel and atmosphere, and thus eliminate the possibility of the tone being impaired by reason of the formation of scaled or partially sealed air pockets in the bridge.

It is found that the perforations or bores 5, which are placed into communication with atmosphere for the same reason, serve to further modulate and enrich the quality of tone.

It will readily be understood that the pianoforte bridge illustrated in the drawings is representative only of the preferred prac tical embodiment of my invention, and that the construction admits of very many modifications Within the scope of my invention. For instance, a plurality of longitudinal channels such as 1 may be formed in the supporting base of the bridge; the tunnels i may be replaced by lateral bores in the sides of the bridge which do not cut into the supporting surface; and the number and disposition of the tunnels i and bores 5 may be varied. It is intended therefore that such modifications shall be included Within the scope of this speciication and the claiming clauses set forth hereinafter.

I claim 1. A bridge for pianofortes and like stringed musical instruments having a longitudinal channel in its under face terminatingshort of the ends, passages being bored through the body 01"- the bridge from the end faces to the channel.

2. A bridge for pianotortes and like stringed musical instruments having a longitudinal channel in its under face terminat ing short of the ends, passages being bored through the body of the bridge from the end faces to the channel, and having lateral channels in its under face at intervals along the length of the bridge.

3. A bridge for pianofortes and like stringed musical instruments having a lon gitudinal channel in its under face terminating short of the ends and having cylindrical passages bored into the body of the bridge through and perpendicular to the under face, said passages terminating short of the upper face of the bridge and being placed into communication with atmosphere by means of holes in the side Walls of the bridge.

JESSE GEORGE JONES. 

